Single-storey rear extensions in Kilmarnock
If you live in Kilmarnock and want more space without moving, a single-storey extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in KilmarnockFrom £20,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time10–16 weeks on site
- Postcode districtsKA1, KA2, KA3
How much does a single-storey extension cost in Kilmarnock?
Prices below are for Kilmarnock, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Kilmarnock: £1,720 to £3,330 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,500 – £24,500 | £24,000 – £31,000 | £30,500 – £40,000 |
| 4 m × 5 m 20 m² | £34,000 – £40,500 | £40,000 – £51,000 | £50,500 – £67,000 |
| 5 m × 6 m 30 m² | £51,000 – £60,500 | £60,000 – £76,500 | £76,000 – £100,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Is a single-storey extension right for your house?
- Homeowners who want open-plan living onto the garden
- Terraced houses that want a deeper kitchen across the full width
- Semi-detached and detached houses with a usable rear garden
Do I need planning permission in Kilmarnock?
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.
Homes in conservation areas, national scenic areas and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Scotland has no Party Wall Act. Where work affects a shared wall or a neighbour's land, we agree access, protection and making good with your neighbour in writing before work starts.
Applications are decided by your council as planning authority.
Covering Kilmarnock
We cover Kilmarnock and the postcode districts KA1, KA2, KA3. Nearby, we also take on projects in Irvine (6 miles), Troon (7 miles), Kilwinning (9 miles), Saltcoats (11 miles).
For homes towards Renfrewshire and Inverclyde, Newton Mearns is around 13 miles away. Scotland's housing includes sandstone villas, terraces and tenements in the cities and plenty of post-war and modern houses and bungalows elsewhere. A building warrant is needed before work starts.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Single-storey extension questions answered
How long does a single-storey extension take to build in Kilmarnock?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Kilmarnock, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a single-storey extension in Kilmarnock?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Book a free site visit in Kilmarnock
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.